My friend, your friend; My friend, your friend; My friend, your friend
Early in my career, I knew a UNIX admin that liked to tell me "vi is your friend". I eventually came to believe that statement and although I rarely use vi anymore, I still think that vi is my friend.
This brings me to some of my best friends today: Google and Wikipedia.
Google is often my best friend: anytime something doesn't work (stupid anti-virus) and I'm just staring at a cryptic error message, I type it into Google and, in my experience, 95%+ I get lots of hits. I may not find the exact answer that I need to solve the problem, but I'll get lots of useful information that puts me on the right path to fixing the issue. The premise behind this for me is that there is no way I'm the only one that has ever dealt with this issue. And, as has been proven time and time again when I do this, I'm right.
One important resource that many people who also use Google for this purpose miss out on though is Google groups. Google groups is an indexed collection of the former Usenet bulletin boards. If I don't find my answer via the Google web search, the group search often does the trick.
Wikipedia is also another great friend to have when you want to know about something, anything, everything. The reference material on Wikipedia is nearly endless; it’s always a great starting point to learn about a topic.
One of the keys, IMHO, to being a good system administrator and system troubleshooter is not necessarily knowing all of, or even most of the answers, its knowing where and how to find the answers.